2.3. Pre-Installation Tasks

Once it has been determined that the system meets the minimum hardware requirements for installing FreeBSD, the installation file should be downloaded and the installation media prepared. Before doing this, check that the system is ready for an installation by verifying the items in this checklist:

Back Up Important Data
Before installing any operating system, always backup all important data first. Do not store the backup on the system being installed. Instead, save the data to a removable disk such as a USB drive, another system on the network, or an online backup service. Test the backup before starting the installation to make sure it contains all of the needed files. Once the installer formats the system's disk, all data stored on that disk will be lost.
Decide Where to Install FreeBSD
If FreeBSD will be the only operating system installed, this step can be skipped. But if FreeBSD will share the disk with another operating system, decide which disk or partition will be used for FreeBSD.
In the i386 and amd64 architectures, disks can be divided into multiple partitions using one of two partitioning schemes. A traditional Master Boot Record (MBR) holds a partition table defining up to four primary partitions. For historical reasons, FreeBSD calls these primary partition slices. One of these primary partitions can be made into an extended partition containing multiple logical partitions. The GUID Partition Table (GPT) is a newer and simpler method of partitioning a disk. Common GPT implementations allow up to 128 partitions per disk, eliminating the need for logical partitions.
The FreeBSD boot loader requires either a primary or GPT partition. If all of the primary or GPT partitions are already in use, one must be freed for FreeBSD. To create a partition without deleting existing data, use a partition resizing tool to shrink an existing partition and create a new partition using the freed space.
A variety of free and commercial partition resizing tools are listed at http://en.wikipedia.org/wiki/List_of_disk_partitioning_software. GParted Live (http://gparted.sourceforge.net/livecd.php) is a free live CD which includes the GParted partition editor. GParted is also included with many other Linux live CD distributions.
Warning:
When used properly, disk shrinking utilities can safely create space for creating a new partition. Since the possibility of selecting the wrong partition exists, always backup any important data and verify the integrity of the backup before modifying disk partitions.
Disk partitions containing different operating systems make it possible to install multiple operating systems on one computer. An alternative is to use virtualization (Chapter 22, Virtualization) which allows multiple operating systems to run at the same time without modifying any disk partitions.
Collect Network Information
Some FreeBSD installation methods require a network connection in order to download the installation files. After any installation, the installer will offer to setup the system's network interfaces.
If the network has a DHCP server, it can be used to provide automatic network configuration. If DHCP is not available, the following network information for the system must be obtained from the local network administrator or Internet service provider:
Required Network Information
1. IP address
2. Subnet mask
3. IP address of default gateway
4. Domain name of the network
5. IP addresses of the network's DNS servers
Check for FreeBSD Errata
Although the FreeBSD Project strives to ensure that each release of FreeBSD is as stable as possible, bugs occasionally creep into the process. On very rare occasions those bugs affect the installation process. As these problems are discovered and fixed, they are noted in the FreeBSD Errata (https://www.freebsd.org/releases/12.1R/errata.html) on the FreeBSD web site. Check the errata before installing to make sure that there are no problems that might affect the installation.
Information and errata for all the releases can be found on the release information section of the FreeBSD web site (https://www.freebsd.org/releases/index.html).

2.3.1. Prepare the Installation Media

The FreeBSD installer is not an application that can be run from within another operating system. Instead, download a FreeBSD installation file, burn it to the media associated with its file type and size (CD, DVD, or USB), and boot the system to install from the inserted media.

FreeBSD installation files are available at www.freebsd.org/where.html#download. Each installation file's name includes the release version of FreeBSD, the architecture, and the type of file. For example, to install FreeBSD 12.1 on an amd64 system from a DVD, download FreeBSD-12.1-RELEASE-amd64-dvd1.iso, burn this file to a DVD, and boot the system with the DVD inserted.

Installation files are available in several formats. The formats vary depending on computer architecture and media type.

Additional installation files are included for computers that boot with UEFI (Unified Extensible Firmware Interface). The names of these files include the string uefi.

File types:

-bootonly.iso: This is the smallest installation file as it only contains the installer. A working Internet connection is required during installation as the installer will download the files it needs to complete the FreeBSD installation. This file should be burned to a CD using a CD burning application.
-disc1.iso: This file contains all of the files needed to install FreeBSD, its source, and the Ports Collection. It should be burned to a CD using a CD burning application.
-dvd1.iso: This file contains all of the files needed to install FreeBSD, its source, and the Ports Collection. It also contains a set of popular binary packages for installing a window manager and some applications so that a complete system can be installed from media without requiring a connection to the Internet. This file should be burned to a DVD using a DVD burning application.
-memstick.img: This file contains all of the files needed to install FreeBSD, its source, and the Ports Collection. It should be burned to a USB stick using the instructions below.
-mini-memstick.img: Like -bootonly.iso, does not include installation files, but downloads them as needed. A working internet connection is required during installation. Write this file to a USB stick as shown in Section 2.3.1.1, “Writing an Image File to USB”.

After downloading the image file, download CHECKSUM.SHA256 from the same directory. Calculate a checksum for the image file. FreeBSD provides sha256(1) for this, used as sha256 imagefilename. Other operating systems have similar programs.

Compare the calculated checksum with the one shown in CHECKSUM.SHA256. The checksums must match exactly. If the checksums do not match, the image file is corrupt and must be downloaded again.

2.3.1.1. Writing an Image File to USB

The *.img file is an image of the complete contents of a memory stick. It cannot be copied to the target device as a file. Several applications are available for writing the *.img to a USB stick. This section describes two of these utilities.

Important:

Before proceeding, back up any important data on the USB stick. This procedure will erase the existing data on the stick.

Procedure 2.1. Using dd to Write the Image

Warning:

This example uses /dev/da0 as the target device where the image will be written. Be very careful that the correct device is used as this command will destroy the existing data on the specified target device.

The dd(1) command-line utility is available on BSD, Linux®, and Mac OS® systems. To burn the image using dd, insert the USB stick and determine its device name. Then, specify the name of the downloaded installation file and the device name for the USB stick. This example burns the amd64 installation image to the first USB device on an existing FreeBSD system.
```
# dd if=FreeBSD-12.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=1M conv=sync
```
If this command fails, verify that the USB stick is not mounted and that the device name is for the disk, not a partition. Some operating systems might require this command to be run with sudo(8). The dd(1) syntax varies slightly across different platforms; for example, Mac OS® requires a lower-case bs=1m. Systems like Linux® might buffer writes. To force all writes to complete, use sync(8).

Procedure 2.2. Using Windows® to Write the Image

Warning:

Be sure to give the correct drive letter as the existing data on the specified drive will be overwritten and destroyed.

Obtaining Image Writer for Windows®
Image Writer for Windows® is a free application that can correctly write an image file to a memory stick. Download it from https://sourceforge.net/projects/win32diskimager/ and extract it into a folder.
Writing the Image with Image Writer
Double-click the Win32DiskImager icon to start the program. Verify that the drive letter shown under Device is the drive with the memory stick. Click the folder icon and select the image to be written to the memory stick. Click [ Save ] to accept the image file name. Verify that everything is correct, and that no folders on the memory stick are open in other windows. When everything is ready, click [ Write ] to write the image file to the memory stick.

You are now ready to start installing FreeBSD.